Microwave oven



FIG. 1 is a top, front, and right side perspective view of our new design for a microwave oven;

FIG. 2 is a front elevation view of our new design;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a left side elevation view thereof;

FIG. 7 is a right side elevation view thereof; and,

FIG. 8 is a front elevation view with the door open. 

The ornamental design for a microwave oven, as shown. 